According to St. Paulβs inspired epistles, the human race is divided into four categories:
1.Β The natural man:Β That is, the fallen son of Adam, as he is, without God. Of him the Apostle says: βThe natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discernedβ (I Cor. 2:14).
2.Β The babe in Christ:Β When a person sees himself as a sinner and trusts Christ as his Saviour, he is βborn againβ and becomes a βbabe in Christβ. But babes can and should grow, so these are exhorted: βAs newborn babes, desire the sincere [pure] milk of the Word, that ye may grow therebyβ (I Pet. 2:2).
3.Β The carnal Christian: One who, though perhaps a Christian for years, has not grown, due to indifference and neglect of the Word of God. He still has to be treated as a babe in Christ. The Corinthian believers were examples of this. Paul had to write them: βIβ¦could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ. I have fed you with milk, and not with meat: for hitherto ye were not able to bear [digest] it, neither yet now are ye ableβ (I Cor. 3:1,2). Everybody loves a baby, but the joy that fills the hearts of loving parents turns to bitterest sorrow if their baby fails to grow.
4.Β The spiritual Christian:Β One who, through prayerful study of the Word of God, has grown to spiritual maturity. He is no longer merely a child of God; he is a βmanΒ of Godβ. We should all βdesire the sincere [pure] milk of the WordΒ that ye may grow therebyβ (I Pet. 2:2) βΒ βTHAT WE HENCEFORTH BE NO MORE CHILDREN, TOSSED TO AND FRO, AND CARRIED ABOUT WITH EVERY WIND OF DOCTRINEβΒ (Eph. 4:14). Let us then heed St. Peterβs inspired exhortation:Β βBUT GROW IN GRACE, AND IN THE KNOWLEDGE OF OUR LORD AND SAVIOUR, JESUS CHRISTβΒ (II Pet.Β 3:18). source